Abstract: A low-carbon, low-alloy and high-formability dual-phase steel having a tensile strength of greater than or equal to 590 MPa, a hot-dip galvanized dual-phase steel, and a manufacturing method therefor by means of rapid heat treatment. The steel comprises the following components, in percentage by mass: 0.04-0.12% of C, 0.1-0.5% of Si, 1.0-2.0% of Mn, P?0.02%, S?0.015%, 0.02-0.06% of Al, and can further comprise one or two of Cr, Mo, Ti, Nb and V, wherein Cr+Mo+Ti+Nb+V?0.5%, and the balance is Fe and other unavoidable impurities. The manufacturing method therefor includes smelting, casting, hot rolling, cold rolling, and rapid heat treatment processes.

Abstract: A low-carbon and low-alloy dual-phase steel and hot-dip galvanized dual-phase steel having tensile strength greater than or equal to 980 MPa and a method for manufacturing by means of rapid heat treatment. The steel has the following chemical components in percentage by mass: C: 0.05-0.17%, Si: 0.1-0.7%, Mn: 1.4-2.8%, P?0.020%, S?0.005%, B?0.005%, and Al: 0.02-0.055%, and may further contain two or more of Nb, Ti, Cr, Mo, and V, Cr+Mo+Ti+Nb+V?1.1%, the balance is Fe and other inevitable impurities. The method for manufacturing the steel comprises: smelting, casting, hot rolling, cold rolling and rapid heat treatment procedures. According to the present invention, the recovery, recrystallization and austenite transformation process of a deformed structure is changed, the nucleation rate is increased, the grain growth time is shortened, grains are refined, the strength of the material is improved, and the performance range of the material is expanded.